A 'short walk' is longer before radiotherapy than afterwards: a qualitative study questioning the baseline and follow-up design

Abstract

BackgroundNumerous studies have indirectly demonstrated changes in the content of respondents' QoL appraisal process over time by revealing response-shift effects. This is the first known study to qualitatively examine the assumption of consistency in the content of the cognitive processes underlying QoL appraisal over time. Specific objectives are to examine whether the content of each distinct cognitive process underlying QoL appraisal is (dis)similar over time and whether patterns of (dis)similarity can be discerned across and within patients and/or items.MethodsWe conducted cognitive think-aloud interviews with 50 cancer patients prior to and following radiotherapy to elicit cognitive processes underlying the assessment of 7 EORTC QLQ-C30 items. Qualitative analysis of patients' responses at baseline and follow-up was independently carried out by 2 researchers by means of an analysis scheme based on the cognitive process models of Tourangeau et al. and Rapkin & Schwartz.ResultsThe interviews yielded 342 comparisons of baseline and follow-up responses, which were analyzed according to the five cognitive processes underlying QoL appraisal. The content of comprehension/frame of reference changed in 188 comparisons; retrieval/sampling strategy in 246; standards of comparison in 152; judgment/combinatory algorithm in 113; and reporting and response selection in 141 comparisons. Overall, in 322 comparisons of responses (94%) the content of at least one cognitive component changed over time. We could not discern patterns of (dis)similarity since the content of each of the cognitive processes differed across and within patients and/or items. Additionally, differences found in the content of a cognitive process for one item was not found to influence dissimilarity in the content of that same cognitive process for the subsequent item.ConclusionsThe assumption of consistency in the content of the cognitive processes underlying QoL appraisal over time was not found to be in line with the cognitive processes described by the respondents. Additionally, we could not discern patterns of (dis)similarity across and within patients and/or items. In building on cognitive process models and the response shift literature, this study contributes to a better understanding of patient-reported QoL appraisal over time.

Thresholds for clinical importance were defined for the European Organisation for Research and Treatment of Cancer Computer Adaptive Testing Core—an adaptive measure of core quality of life domains in oncology clinical practice and research

“…In fact, for some of the PROMIS measures, the general population mean overlapped with the categories for mild symptom levels [27,28]. This could indicate a response shift phenomenon [29], resulting in an underestimation of the true difference between cancer patients and the general population but may also reflect the high percentage of individuals suffering from (chronic) diseases in the general population. In the normative sample for the EORTC CAT Core [9], for example, 61.0% of the participants from the general population reported at least one health condition, with chronic pain (23%), arthritis (13%), and diabetes (10%) being most common.…”

Cognitive reserve and appraisal in multiple sclerosis

“…For example, HIV/AIDS patients who reported better mental health than would be expected based on overt health status used appraisal strategies such as avoiding to think about things that are disappointing, worrisome, or difficult (Bobinski and Lipinski, 2009). The cognitive processes underlying patient response to patientreported outcome measures have also been found to change over time in cancer patients, and to be affected by treatment side-effects (Taminiau-Bloem et al, 2010). These findings suggest that QOL appraisal processes are relevant to resilience and adaptability.…”

Daily life and life quality 3 years following prostate cancer treatment

“…Fluctuation over time is found in the work of Taminiau-Bloem et al who reported major changings in answering from baseline to follow up, in a sample of 50 cancer patients in aspects underlying OQL appraisal of e.g. taking a short walk, pain, fatigue, worry and overall quality of life [13]. Their finding calls for caution when giving attention to both quantitative and qualitative follow-up assessment.…”